每个人我都是程序世界的新手，我遇到了一个问题，我的请求与使用 JAVA 代码的 Android 平板电脑与台式电脑之间的通信有关。
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class HelloWorldServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public HelloWorldServlet() {
super();
}
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
PrintWriter out = response.getWriter();
out.println("Hello Android !!!!");
}
}
上面的代码是我的 servlet 代码，它在我的本地系统服务器（Tomcat 6.0）中运行，我通过 println 发送消息，我想在另一个系统中运行的 Android 应用程序中接收相同的消息。现在我要发布我在另一个系统上运行的 android 代码。
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
public class HttpGetServletActivity3 extends Activity implements
OnClickListener {
Button button;
TextView outputText;
public static final String URL =
"http://192.168.0.2:9999/HttpGetServlet/HelloWorldServlet";
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
findViewsById();
button.setOnClickListener(this);
}
private void findViewsById() {
button = (Button) findViewById(R.id.button);
outputText = (TextView) findViewById(R.id.outputTxt);
}
public void onClick(View view) {
GetXMLTask task = new GetXMLTask();
task.execute(new String[] { URL });
}
private class GetXMLTask extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... urls) {
String output = null;
for (String url : urls) {
output = getOutputFromUrl(url);
}
return output;
}
private String getOutputFromUrl(String url) {
StringBuffer output = new StringBuffer("");
try {
InputStream stream = getHttpConnection(url);
BufferedReader buffer = new BufferedReader(
new InputStreamReader(stream));
String s = "";
while ((s = buffer.readLine()) != null)
output.append(s);
} catch (IOException e1) {
e1.printStackTrace();
}
return output.toString();
}
// Makes HttpURLConnection and returns InputStream
private InputStream getHttpConnection(String urlString)
throws IOException {
InputStream stream = null;
URL url = new URL(urlString);
URLConnection connection = url.openConnection();
try {
HttpURLConnection httpConnection = (HttpURLConnection) connection;
httpConnection.setRequestMethod("GET");
httpConnection.connect();
if (httpConnection.getResponseCode() == HttpURLConnection.HTTP_OK) {
stream = httpConnection.getInputStream();
}
} catch (Exception ex) {
ex.printStackTrace();
}
return stream;
}
@Override
protected void onPostExecute(String output) {
outputText.setText(output);
}
}}
这里 192.68.0.2 是在我的本地系统中运行 servlet 代码的系统的 IP 地址（Tomcat6.0 服务器的端口号为 9999）。但它对我不起作用。两个系统都在同一个 wifi 网络中 任何帮助都是真的非常感激。在此先感谢大家